@book { IchDieAutobiographie,
    title = "Ich. Die Autobiographie",
    author = "Helmut {Berger} and Holde {Heuer}",
    year = "2013",
    publisher = "hey! publishing",
    address = "München, Deutschland",
    doi = "10.3239/9783942822404",
    url = "https://www.heypublishing.com/document/207287"
}